1. Technical Field
Embodiments of the present disclosure relate to security surveillance technology, and particularly to a method for adjusting a focal length of a camera.
2. Description of Related Art
Currently, cameras are used to perform security surveillance by capturing images of specified spaces, and sending the captured images to a monitoring computer. Often, a focal length of the camera needs to be adjusted according to a change in the area around the camera. A first method is to use a camera that can automatically adjust the focal length of the camera. However, these cameras are often expensive. A second method is to adjust the focal length of each of the cameras manually. However, the second method needs at least two persons to adjust the focal length of the camera. In this method, a first person adjusts the focal length of the camera while a second person checks the adjustment on a monitor at the control center and gives feedback to the first person. It is inconvenient to adjust a plurality of cameras using the second method. Therefore, a prompt and efficient method for adjusting a focal length of a camera is desired.